Coil for dynamo-electric machines.



J. D. FORRER.

COIL FOR DYNAMO ELECTRIC MACHINES.

APPLICATION FILED JULY 24, 1908.

Patented May 17, 19 10.

2 SHEETSSHEET 1.

fivgm R BY mu) WITNESSES:

ATTORNEY J. D. PORRER.

COIL FOR DYNAMO ELECTRIC MACHINES.

APPLICATION FILED JULY 24,1908.

Patented May '17, 1910.

2 SHEETS-SHEET 2 INVENTOR WITNESSES:

ATTORN EY -UNITED STATES PATENT QFFIGE. e 1

JOSEPH 1). FORRER, or rims-Bone, PENNSYLVANIA, rissieNdn, BY MESNE MENTS, T0 wEs'rrNenoUsE ELEcrnro & N; NUFAc'I-URI G COMPANY, PITTSBURG, PENNSYLVANIA, A oonroRArroN or'rENNsYLvANrnQ CQIL FOR DYNAMO-ELECTRIC MACHINES.

T 0 all whom it may concern;

Be it knownthat I, Josnrri D. Forum, a citizen of the United States, and a resident of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Coils for Dy-, namo-Electric Machines, of which the following isa specification.

My invention relates to coils for dynamoelectric ,machines and it has special reference to coils of the so-called diamond type which are adap ted to form parts of the wave windings of commutator type machines.-

T he object of my invention is to provide a coil of the'class above indicated that shall be simple in construction, relatively easy to ,wind and specially economical of space.

\Vhen directcurrent electric motors and generators, or other dynamo-electric ma- ,chines having commutators, are provided with complete wave windings having coils of the diamond type, the end connecting portions of the assembled coils are close the ins a) I to ether and form two layers, one within the ot r. In the prior art, the coil leads usually were so related to-the remainder of the coil tha't'at least one of them was necessarily b'rojugh adially inward or-outward from of the layers referred to above. The-leads were then bent in opposite directions and carried to the commutator bars along any suitable lines following the general direction of the axis of the machine.

According to my present invention, the short radial portions of the leads which were usually crowded between adjacent coils are entirely avoided, the leads being so brought out as to form a continuation of. the innermost and outermost conductors of the coils so that they may extend directly to the proper commutator bars and at the same time the usual short radius bends in the coil are reduced to a minimum.

Figure 1 of the accompanying drawings is a side elevation of a complete coil assembled in. the core of a dynamo-electric machine in the usual manner, the core being indicated by broken lines. Fig. 2 is a plan view of coil and core portion shown in Fig. 1'. Fig. 3 is a detail view of adjacent portions of the ends of two coils. Figs. 4 and 5 are views similar to Figs. 1 and 2 of a coil having four turns or convolutions and wound in accordance with my invent on.

Specification of Letters Patent. Patgntefl llIay 1T, liil l iltl j I 1 Application fi1ed Ju1y 24, 1808. Serial No. 445,280.

Referring to Figs. 1, 2, and 3. of the drawnigs, the 0011 here illustrated comprises a complete or closed multi-strand turn 0; and

an open multi-strand turn b.- The strands(;-

of whichthe coil is wound are side by-side and the turns of the 0011 are one above another. The general form of the coil is that of the well known diamond type having parallel straight portions 65 and c which arelocated in the usual core slots of a dynamoelectric machine and substantially J-shaped end connecting portions 7 and g which join the extremities of, the straight portions (:3 and e that project from the core slots. The coil leads h and 2' project from the straight portionsd and e and at the same end of the core of the machine, lead 72. forming a continuation of the undermost turn of the straight portion (Z and the lead a forming a continuation of the uppermost turn of the straight portion 6. These leads may, of course, extend to the commutator of the machine in any suitable manner but usually form, in a. wave type of Winding, angles with the straight portions of the coil which correspond to those of the adjacent portions of the end connector.

5 Referring specially to Fig. 2 of the drawings, it will be understood by those skilled in the art. that the outermost strand 1 in the jacent' to the strand 1 in the lead '5 must still bear the same'relation to the strand 1 in the lead it and the innermost strand 4. of

'lead 2' must be the outermost strand of lead.

it. In order to accomplish this result, it has hitherto been usual to so bend the turns of the coils at the middle points of the end connecting portions f and g as to turn the strands over three times in the two convolutions of which the coil is composed, thereby forming the usual off-set bends and finally bringing out the leads in the desired relation.

I have considerably simplified the coils ofthe prior art in such manner that the objectionable bends in the leads, to which reference has already been made, are avoided. The end connecting portiong of my improved coil isprovided with abend 7a which 1 term, for convenience; an off-setbend in which the strands are turned over.

tion d to the lead 72,.

in the lead 2', instraight portione, in the end connecting pUltlOIl f and in the straight portlon d, is here changed from the outside ,to

the inside and, in the latter position, extends again through straight portion e, the end connecting portion f, and the straight por- In a similar manner, the other strands of the coil are so bent as to maintain their proper relation. In the end connecting portion f, however, the posltion of the strands is unchanged and only a slight bend is necessary, as shown in Fig.

' 3, in'order-that a plurality of coils may be so wound, in the usual manner, as to fit togetllfl' into a small space at the ends of the core member. The distance beyond the core member necessarily occupied by the end 0011 neeting portions f is materially reduced by I the use of my lmproved coil.

Round-wire coils may advantageously'be formed in accordance with my invention,

but the advantages of this method are more apparent in coils-which are formed of strap or square-wire conductors, since it is relatively difficult to make short radius edge-' wise bends in strap conductors. Thus it is possible to secure the well known advan-' tags of the strap Winding, which is more economical of space in the core slots, with'a minimum number of undesirable bends.

'. Referrin gto Figsfl and 5 the coil here illustrated comprises three complete or closed turns l, m, and 0 corresponding to turn a in the other figures, and oneopen turn-p that corresponds to the turn 6. The

advantages of my invention when applied to a four turn coil' are specially apparent over the most improved coils of the prior 1 art for the reason that four turn coils of this general type, arranged to avoid the objectional feature of hend'ng one of the leads radially to bring it o t from between the,

turns, would com rise four ofi-setbends at one end and three at the other which would practically bar its use. On the other hand, accordin to my invention, four turn coils may be eadily constructed (see Fig. ,1 5) having only three off-set bends w, y, and z W-htt zh are not objectionable. The end connecting portion f in the four turn coil 1s provided with-a slight bend, asin the two turn coil, in order that a plurality 0t coils ma y be fitted together. By turning the CO1 ductors over three times in the four turns located one -a ove another, the strands of said turns being located side by side and reversed inposition once in each closed turn of the coil.

2. A. wave winding coil for dynamo-electric machines comprising one complete and one open multi-strand turn. the closed turn of which hasan off-set bendand the strands being reversed in position at the off-setbend.

3. A coil for. dynamo-electric machines comprising a plurality of multi-strand turns having substantially parallel straight portions, V-shaned end connecting portions and an off-set bend in one of the said end con necting portions, the position of the strands being reversed on opposite sides of said otfset bend. i

4. A coil comprising a plurality of multistrand turns having substantially parallel straight portions adapted to be included in;

the core slots of a dynamo-electric machine,

V-shaped end connecting portions and an offaset' bend in one of the said end connecting portions, the relative positions of the strands being the same throughout the coil except that they are disposed in reverse order at opposite sides of the off-set bend.

In testimony whereof, I have hereunto subsqribed my name this 14th dayof July,

J. D. 'FORRER.v v Witnesses:

H. E. DYCLIE, BIRNEY Hnsns. 

